Oct. 12, 2011 -- People with Barrett's esophagus, a complication of heartburn and acid reflux disease, are at risk of developing a deadly kind of cancer at much lower rates than doctors previously believed, a new study shows.

The study is published in the New England Journal of Medicine.

Researchers collected information on more than 11,000 people in Denmark who were diagnosed with Barrett's esophagus to see how many would go on to develop an aggressive cancer called adenocarcinoma of the esophagus.

In Barrett's esophagus the lining of the esophagus, the muscular tube that connects the throat to the stomach, abnormally changes after repeated exposure to stomach acid.

The condition may affect as many as 1 million American adults. It is most commonly diagnosed in men who are white, overweight, and over age 50.

Previous studies have found that Barrett's esophagus increases the risk of getting cancer of the esophagus. This study found that the risk of cancer, while still elevated, is much lower than previously believed, about 0.12% per year. That equals about one case of cancer diagnosed each year for every 860 people with Barrett's. That's about an 80% lower risk than previously believed.

Those findings echo another study published earlier this year in the Journal of the National Cancer Institute. That study, of 1.7 million people in Northern Ireland, estimated the yearly risk of cancer of the esophagus in people with Barrett's to be around 0.13%, or one case of cancer each year for every 769 people diagnosed with the condition.

Researchers say the findings mean that it may not be helpful or cost-effective for doctors to give some people with Barrett's regular, invasive tests to keep looking for cancer.

"I think it's going to be a landmark study," says Heiko Pohl, MD, a gastroenterologist and associate professor of medicine at Dartmouth Medical School and Dartmouth Medical Center in Lebanon, N.H. Pohl studies the risks and benefits of cancer screening tests. He was not involved in the current research.

"This is going to help us get a better understanding of the magnitude of the problem, what Barrett's really means," he tells WebMD.

Many patients with Barrett's are offered surgery to freeze or burn off the abnormal tissue, even if they don't have any signs of cancer.

"Hopefully this study will put a little brake on the whole hype," Pohl says.

Questions About Cancer Screening

The study is likely to fuel an already highly charged debate about whether the risks of some kinds of cancer screening tests outweigh the benefits of early detection.

Earlier this week, the U.S. Preventive Services Task Force recommended against routine PSA screening for prostate cancer unless a man has suspicious symptoms. That's because studies have failed to find a lifesaving benefit for that test and positive tests often lead to treatments that can have side effects, like erectile dysfunction and incontinence.

But the debate over screening for cancer of the esophagus may be even more pitched because the cancer is so lethal and it's on the rise in the U.S.

"If you get the cancer, you don't survive, by and large," says Peter J. Kahrilas, MD, a gastroenterologist at Northwestern Memorial Hospital and a professor in the department of medicine at the Feinberg School of Medicine at Northwestern University in Chicago.

"The only strategy for surviving the cancer, and this is the irony of the whole thing, is early detection," says Kahrilas, who was not involved in the research but wrote an editorial on the study.

To many doctors, that means a diagnosis of Barrett's, one of the few established risk factors for cancer of the esophagus, shouldn't be ignored.

"As an esophageal surgeon who deals with esophageal cancer and who has to at times tell people, 'I'm sorry, this is now metastatic [the cancer has spread], I can't operate on you,' I have a hard time reconciling inside of myself telling someone with Barrett's, 'You have Barrett's. Don't worry about it. You don't need any further examination.' That makes me very, very nervous," says Christian G. Peyre, MD, an assistant professor of surgery at the University of Rochester Medical Center in New York. Peyre was not involved in the study.

The better question in Peyre's mind is how often people with Barrett's need to be checked.

Guidelines suggest doing a test called an endoscopy with a biopsy every two to five years in people who have Barrett's esophagus or even persistent heartburn.

The endoscopy test involves inserting a lighted tube through the mouth into the esophagus. A biopsy of the esophagus can be performed during the procedure. The test should be repeated more frequently if precancerous cells are found.

Indeed, the study found evidence that cancer was more likely in people who had Barrett's esophagus with precancerous cells, called dysplasia.

"I think that all patients with new GERD [acid reflux] symptoms should undergo endoscopy," says study researcher Peter Funch-Jensen, MD, a researcher in the department of clinical medicine at Aarhus University in Denmark, in an email.

Still, the diagnosis of dysplasia is subjective, since it relies on the judgment of the doctor. The American Gastroenterological Association recommends that a diagnosis of dysplasia be confirmed by at least one additional pathologist.

Routine Surveillance of Barrett's Esophagus?

If no dysplasia is found, "no routine surveillance is probably indicated," Funch-Jensen says.

"The second people get told they have a cancer or a risk for cancer, they start to not sleep at night very well, so it becomes a big issue," says Brian Reid, MD, PhD, member of the human biology division at Fred Hutchinson Cancer Research Center in Seattle. Reid is also principal investigator of the Seattle Barrett's Esophagus Research Program.

"The fundamental difficulty that we have is that there's widespread screening for Barrett's, yet probably only 5% or so will go on to develop a cancer during their lifetime. The remaining 95% will die of something else," Reid says.

Experts say the quandary will likely only be solved by the discovery of new indicators for cancer of the esophagus and better tests.

"We have to come up with a better way of screening," says Kahrilas. "We have to come up with a way of screening that is inexpensive, unobtrusive, and cost-effective."